U.S. patent application number 12/224900 was filed with the patent office on 2009-03-12 for polymeric electrolyte, method for production thereof, and electrochemical element.
Invention is credited to Hitoshi Shobukawa, Akira Yoshino.
Application Number | 20090065730 12/224900 |
Document ID | / |
Family ID | 39183738 |
Filed Date | 2009-03-12 |
United States Patent
Application |
20090065730 |
Kind Code |
A1 |
Yoshino; Akira ; et
al. |
March 12, 2009 |
Polymeric Electrolyte, Method for Production Thereof, and
Electrochemical Element
Abstract
A polymeric electrolyte comprising: a polymeric material and an
electrolyte salt; or a polymeric material, a solvent and an
electrolyte salt, wherein a copolymer composed of 50 to 99 mol % of
an ethylenically unsaturated compound and 1 to 50 mol % of carbon
monoxide comprises 66.7 to 100 wt % of the polymeric material.
Inventors: |
Yoshino; Akira; (Tokyo,
JP) ; Shobukawa; Hitoshi; (Tokyo, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
39183738 |
Appl. No.: |
12/224900 |
Filed: |
September 10, 2007 |
PCT Filed: |
September 10, 2007 |
PCT NO: |
PCT/JP2007/067598 |
371 Date: |
September 9, 2008 |
Current U.S.
Class: |
252/62.2 ;
429/303; 429/306 |
Current CPC
Class: |
C08L 73/00 20130101;
H01M 6/181 20130101; H01M 2300/0082 20130101; Y02E 60/10 20130101;
H01M 2300/0025 20130101; H01G 9/038 20130101; Y02E 60/13 20130101;
C08L 71/02 20130101; H01B 1/122 20130101; H01M 2300/0091 20130101;
H01M 10/0525 20130101; H01M 10/0565 20130101; C08G 67/02 20130101;
H01G 11/56 20130101; C08L 71/02 20130101; C08L 2666/14 20130101;
C08L 73/00 20130101; C08L 2666/22 20130101 |
Class at
Publication: |
252/62.2 ;
429/303; 429/306 |
International
Class: |
H01G 9/038 20060101
H01G009/038; H01M 10/40 20060101 H01M010/40; H01M 6/14 20060101
H01M006/14 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 11, 2006 |
JP |
2006-245320 |
Sep 11, 2006 |
JP |
2006-245321 |
Sep 11, 2006 |
JP |
2006-245322 |
Claims
1. A polymer electrolyte comprising a polymer material and an
electrolyte salt, or a polymer material, a solvent and an
electrolyte salt, wherein 66.7% by weight to 100% by weight of the
polymer material is a copolymer of 50 to 99 mol % of an
ethylenically unsaturated compound and 1 to 50 mol % of carbon
monoxide.
2. The polymer electrolyte according to claim 1, wherein a weight
ratio of the solvent to a total of the solvent and the polymer
material is 0 or more and less than 33.3%.
3. The polymer electrolyte according to claim 2, wherein 100% by
weight of the polymer material is the copolymer.
4. The polymer electrolyte according to claim 1, wherein the
copolymer comprises an alternative copolymer of an ethylenically
unsaturated compound and carbon monoxide.
5. The polymer electrolyte according to claim 1, 3 or 4, wherein
the electrolyte is an all solid-type polymer electrolyte comprising
the alternative copolymer and the electrolyte salt.
6. The polymer electrolyte according to any one of claims 1 to 4,
wherein the electrolyte is a gel-type polymer electrolyte
comprising the alternative copolymer, the electrolyte salt and the
solvent.
7. The polymer electrolyte according to any one of claims 1 to 4,
wherein the polymer material is a crosslinked polymer material.
8. A process for producing the polymer electrolyte according to any
one of claims 1 to 4, comprising the steps of: dissolving a polymer
material comprising 66.7% by weight to 100% by weight of a
copolymer of 50 to 99 mol % of an ethylenically unsaturated
compound and 1 to 50 mol % of carbon monoxide in a solution in
which 30% by weight to 90% by weight of an electrolyte salt is
dissolved in a solvent; forming the resulting mixture into an
arbitrary shape; and removing a part or all of the solvent.
9. The process according to claim 8, wherein 100% by weight of the
polymer material is the copolymer.
10. The process according to claim 8, wherein the copolymer
comprises an alternative copolymer of an ethylenically unsaturated
compound and carbon monoxide.
11. An electrochemical device characterized by using the polymer
electrolyte according to any one of claims 1 to 4.
Description
TECHNICAL FIELD
[0001] The present invention relates to a polymer electrolyte with
high ionic conductivity comprising a copolymer of an ethylenically
unsaturated compound and carbon monoxide, and a process for
producing the same. The present invention further relates to an
electrochemical device using the polymer electrolyte which has
excellent liquid leakage resistance, heat resistance, and safe
performance.
[0002] Hereinafter, the copolymer of an ethylenically unsaturated
compound and carbon monoxide includes examples of an alternative
copolymer as well, and both are also collectively represented as an
(alternative) copolymer depending on the context of
explanation.
BACKGROUND ART
[0003] As portable information devices such as a laptop computer
and a cellular phone have become popular, a demand for
electrochemical devices such as a primary battery, a secondary
battery and an electric double layer capacitor used as power
supplies for the devices has rapidly increased. It is particularly
required for these electrochemical devices to be compact and light,
and from into a thin film, and simultaneously improvement of
reliability is also expected. In recent years, in addition to power
supplies for portable information devices new applications such as
power supplies for a hybrid electric car and energy storage have
been developed, and thus have been required to further improve the
reliability.
[0004] An electrolyte solution in which an electrolyte salt is
dissolved in a solvent is generally used in an electrochemical
device, and when leakage liquid and further an electrolyte solution
are non-aqueous electrolyte solutions, troubles such as catching
fire and setting fire are caused, which make a major factor in
impairing the reliability. Accordingly, these problems can be
solved by using a solid electrolyte in place of an electrolyte
solution. Particularly, a polymer electrolyte is easy to form a
thin film and has excellent mechanical properties and flexibility,
and therefore is a highly promising material.
[0005] From such viewpoints, many investigations with respect to a
polymer electrolyte have been made over the years and there have
been many proposals since it was firstly reported that ionic
conductivity was produced by composite formation of a certain kind
of alkali metal salt with a poly(ethylene oxide)-based high polymer
(see Non-Patent Document 1).
[0006] Patent Document 1 proposes semi-solid gel-type polymer
electrolytes comprising methyl polymethacrylate, electrolyte salts
such as LiClO.sub.4 or LiBF.sub.4, and organic solvent.
[0007] Patent Document 2 proposes an electrochemical generator
using an all solid-type polymer electrolyte in which an electrolyte
salt is solid-solubilized in a high polymer containing a heteroatom
such as oxygen or nitrogen, and poly(ethylene oxide) and a
polyamine, are shown as examples of a polymer material in the
document.
[0008] Patent Document 3 proposes a gel-type polymer electrolyte
composition in which an electrolyte salt is dissolved in a mixture
of a high polymer having a dielectric constant of 4 or more and an
organic solvent having a dielectric constant of 10 or more, and
shows that examples of a polymer material satisfying such a
requirement include nitrocellulose, a phenol resin, polyvinylidene
fluoride, polyacrylonitrile and chlorosulfonated polyethylene.
[0009] Patent Document 4 discloses a lithium solid electrolyte cell
using metal lithium as a negative electrode and metal chalcogenide
as a positive electrode, and shows that examples of the solid
electrolyte include polymer electrolytes using a vinylidene
fluoride copolymer, polyvinyl chloride, polyvinyl acetate,
polyvinyl pyrrolidone or the like.
[0010] Patent Document 5 proposes an ionic conductive solid
composition using a polymer material and discloses polysiloxane as
an excellent polymer material.
[0011] Patent Document 6 discloses a hybrid ion conductor using an
oxyethylene (meth)acrylate polymer.
[0012] Further, Patent Document 7 discloses an ionic conductive
crosslinking-type resin composition based on an aliphatic epoxy
resin, Patent Document 8 discloses a polymer electrolyte based on
polyphosphazene, Patent Document 9 discloses an ionic conductive
polymer complex comprising polyalkylene carbonate, metal salts and
organic solvent, Patent Document 10 discloses a polymer solid
electrolyte and a polymer solid electrolyte cell using
polyurethane, and Patent Document 11 discloses, for example, an
ionic conductive composition based on polyvinyl alcohol.
[0013] As described above, with respect to a polymer electrolyte,
two kinds of polymer materials of an all solid-type polymer
electrolyte comprising a polymer material and an electrolyte salt
and a gel-type polymer electrolyte mixed with a polymer material
and an electrolyte salt, and further a solvent have been proposed,
but the following significant problem still remains.
[0014] That is, no material achieving practically satisfying ionic
conductivity was proposed for an all solid-type polymer
electrolyte. Further, a large amount of solvent had to be mixed to
obtain practical ionic conductivity in the case of a gel-type
polymer electrolyte. Therefore, from the viewpoint of reliability,
reliability of each of these electrolytes is only a level better
than that of an electrochemical device using a conventional liquid
electrolyte, and thus high reliability originally expected for a
polymer electrolyte was not achieved.
[0015] Thereafter, keeping in line with commercialization of a
lithium ion secondary battery, it was proposed to apply a polymer
electrolyte to a lithium ion secondary battery (see Patent Document
12). Thereby, research of a polymer electrolyte has been actively
conducted and a lithium ion secondary battery using a gel-type
polymer electrolyte was commercialized. However, as described
above, this gel-type polymer electrolyte contained a large amount
of solvent, and high reliability originally expected for a polymer
electrolyte was not obtained. As a result, in a lithium ion
secondary battery market, most of the product is occupied by the
one using a liquid electrolyte and the market share of a lithium
ion secondary battery using a gel-type polymer electrolyte is
extremely small. In order to solve this problem, various polymer
materials have been investigated since then, and Patent Document 13
proposes an ionic conductive polymer electrolyte comprising a
polymer A having a carbonyl group (1 to 40% by weight), a
poly(vinylidene fluoride)-based polymer B (20 to 70% by weight), a
metal salt C (1 to 50% by weight) and an organic solvent D (20 to
85% by weight). Herein, preferable examples of the polymer A having
a carbonyl group include polyesters, polycarbonates and polyester
carbonates, and the other examples thereof further include
polyamides, polypeptides, polyurethanes and polyketones. However,
this system also contains a large amount of organic solvent, and
the ionic conductivity is not always satisfying.
[0016] As described above, although a lithium ion secondary battery
using a gel-type polymer electrolyte is put into practical use for
only partial application of compact consumer batteries, major
problems still remain in development of a polymer electrolyte in
the present situation.
[0017] Patent Document 1: JP-A-54-104541
[0018] Patent Document 2: JP-A-55-098480
[0019] Patent Document 3: JP-A-57-143356
[0020] Patent Document 4: JP-A-58-075779
[0021] Patent Document 5: JP-A-59-230058
[0022] Patent Document 6: JP-A-60-031555
[0023] Patent Document 7: JP-A-60-248724
[0024] Patent Document 8: JP-A-61-254626
[0025] Patent Document 9: JP-A-62-030147
[0026] Patent Document 10: JP-A-01-197974
[0027] Patent Document 11: JP-A-01-284508
[0028] Patent Document 12: JP-A-01-241767
[0029] Patent Document 13: JP-A-11-060870
[0030] Non-Patent Document 1: P. V. Wright, Polymer, 14, 589
(1973)
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0031] As described above, it was difficult to satisfy both the
ionic conductivity and reliability in a conventional polymer
electrolyte. Particularly in recent years, the field of large-scale
application such as a hybrid electric car requiring higher
reliability has been developed, and the requirement of intrinsic
reliability which a polymer electrolyte should originally have has
been increased more than ever. Further, a polymer electrolyte is
usually used at a high voltage of 100 V or more in this field of
large-scale application, and a polymer electrolyte having high
ionic conductivity and high reliability has been required for
realizing a bipolar electrode that is the most rational electrode
structure for use at such high voltages.
[0032] The present invention has been made to solve these problems
and provides an all solid-type polymer electrolyte having high
ionic conductivity by selecting a specific polymer material, a
gel-type polymer electrolyte having high ionic conductivity by
adding a small amount of a solvent within an extent not impairing
reliability, and a process for producing these electrolytes.
Further, the present invention also provides an electrochemical
device having excellent output characteristics and high reliability
by using these polymer electrolytes.
Means for Solving the Problems
[0033] The present inventors have made intensive studies in order
to solve the above-mentioned problems. As a result, we have found
that the above-mentioned problems can be solved by using an
(alternative) copolymer of an ethylenically unsaturated compound
and carbon monoxide, leading to the present invention.
[0034] A polymer electrolyte of the present invention is a polymer
electrolyte comprising a polymer material and an electrolyte salt,
or a polymer material, a solvent and an electrolyte salt,
characterized in that 66.7% by weight to 100% by weight of the
polymer material is a copolymer of 50 to 99 mol % of an
ethylenically unsaturated compound and 1 to 50 mol % of carbon
monoxide.
[0035] Further, the polymer electrolyte of the present invention is
a polymer electrolyte comprising a polymer material and an
electrolyte salt, or a polymer material, a solvent and an
electrolyte salt, characterized in that 100% by weight of the
polymer material is a copolymer of 50 to 99 mol % of an
ethylenically unsaturated compound and 1 to 50 mol % of carbon
monoxide, and a weight ratio of the solvent to a total of the
solvent and the polymer material is 0 or more and less than
33.3%.
[0036] Further, the polymer electrolyte of the present invention is
characterized in that the copolymer comprises an alternative
copolymer of an ethylenically unsaturated compound and carbon
monoxide.
[0037] Further, a process for producing the polymer electrolyte of
the present invention is characterized by comprising the steps of:
dissolving a polymer material comprising 66.7% by weight to 100% by
weight of a copolymer of 50 to 99 mol % of an ethylenically
unsaturated compound and 1 to 50 mol % of carbon monoxide in a
solution in which 30% by weight to 90% by weight of an electrolyte
salt is dissolved in a solvent; forming the resulting mixture into
an arbitrary shape; and removing a part or all of the solvent.
[0038] Further, the process for producing the polymer electrolyte
of the present invention is characterized by comprising the steps
of: dissolving a copolymer of 50 to 99 mol % of an ethylenically
unsaturated compound and 1 to 50 mol % of carbon monoxide in a
solution in which 30% by weight to 90% by weight of an electrolyte
salt is dissolved in a solvent; forming the resulting mixture into
an arbitrary shape; and removing a part or all of the solvent.
[0039] Further, the process for producing the polymer electrolyte
of the present invention is characterized by comprising the steps
of: dissolving an alternative copolymer of an ethylenically
unsaturated compound and carbon monoxide in a solution in which 30%
by weight to 90% by weight of an electrolyte salt is dissolved in a
solvent; forming the resulting mixture into an arbitrary shape; and
removing a part or all of the solvent.
[0040] Further, an electrochemical device of the present invention
is characterized by using the above-mentioned polymer electrolyte
of the present invention.
EFFECTS OF THE INVENTION
[0041] The polymer electrolyte of the present invention will
achieve an effect satisfying both high ionic conductivity and
reliability. In addition, the electrochemical device of the present
invention will achieve an effect having high reliability and
excellent output characteristics.
BEST MODE FOR CARRYING OUT THE INVENTION
[0042] Hereinafter, the present invention will be specifically
described.
[0043] One of the characteristics of the present invention is that
an (alternative) copolymer of an ethylenically unsaturated compound
and carbon monoxide is used as a polymer electrolyte.
[0044] A copolymer of an ethylenically unsaturated compound such as
ethylene and propylene, and carbon monoxide has photosensitivity
based on a carbonyl group contained in a main chain of the polymer,
and attention has been paid to this copolymer as a photosensitive
polymer material and an easily photodisintegrated polymer material
for long time. It is known as the manufacturing method that the
copolymer is obtained by thermal polymerization or radical
polymerization of an ethylenically unsaturated compound and carbon
monoxide in the presence of an initiator such as peroxides, as
disclosed in, for example, JP-A-50-34087 and JP-A-53-128690.
[0045] The present invention is based on the finding that the
polymer electrolyte having high ionic conductivity can be obtained
by using this copolymer of an ethylenically unsaturated compound
and carbon monoxide.
[0046] However, the copolymer obtained in the above-mentioned
radical polymerization was a random copolymer having a low carbon
monoxide content.
[0047] Meanwhile, there has been recently found a method
copolymerizing an ethylenically unsaturated compound with carbon
monoxide are copolymerized by coordination polymerization using a
transition metal compound, such as palladium as a catalyst, as
disclosed in, for example, JP-A-01-092222. An alternative copolymer
in which an ethylenically unsaturated compound and carbon monoxide
are alternatively copolymerized can be obtained by this
coordination polymerization.
[0048] The present invention is also based on the finding that a
polymer electrolyte having high ionic conductivity can be obtained
by using an alternative copolymer of an ethylenically unsaturated
compound and carbon monoxide.
[0049] Examples of the ethylenically unsaturated compound used in
the present invention include .alpha.-olefins such as ethylene,
propylene, 1-butene, 1-hexene, 1-octene and 1-decene; alkenyl
aromatic compounds such as styrene, .alpha.-methylstyrene and
p-methylstyrene; cyclic olefins such as cyclopentene, norbornene
and 5-methylnorbornene; vinyl halides such as vinyl chloride; and
acrylic acid esters such as ethyl acrylate and methyl
methacrylate.
[0050] Among these, a preferable ethylenically unsaturated compound
is .alpha.-olefins, and a more preferable ethylenically unsaturated
compound is .alpha.-olefins having 2 to 4 carbon atoms.
[0051] These ethylenically unsaturated compounds can be used singly
or as a mixture of a plurality thereof. When a plurality of the
compounds are used for the alternative copolymer, any one of
ethylenically unsaturated compounds may be alternatively
copolymerized with carbon monoxide.
[0052] As a polymerization method for a copolymer that is not an
alternative copolymer, polymerization by a thermal polymerization
initiator as described above is possible, and examples of the
initiator include peroxides such as benzoyl peroxide, lauroyl
peroxide, di-t-butyl peroxide, dicumyl peroxide and t-butyl
hydroperoxide; and azo compounds such as azobisisobutyronitrile and
azobisvaleronitrile. As a polymerization form, bulk polymerization,
solution polymerization, slurry polymerization and the like can be
selected.
[0053] As a coordination polymerization catalyst for producing an
alternative copolymer, a combination of three components of a
transition metal compound, particularly a palladium compound, a
compound acting as a ligand of palladium and an anion is preferred.
As the palladium compound, carboxylates, phosphates, carbamates,
sulfonates, halides of palladium or the like are used, and specific
examples thereof include palladium acetate, palladium butyrate,
palladium trifluoroacetate, palladium phosphate, palladium
acetylacetonate, palladium trifluoromethanesulfonate, palladium
chloride, and
bis(N,N-diethylcarbamate)bis(diethylamino)palladium.
[0054] Examples of the compound acting as a ligand of palladium
include amine-based compounds and phosphine-based compounds.
Further, examples of the anion include an anion of an inorganic
acid such as sulfuric acid, nitric acid, perchloric acid or
phosphoric acid; and an anion of an organic acid such as
trifluoroacetate, methanesulfonic acid and trifluoromethanesulfonic
acid.
[0055] Generally, an ethylenically unsaturated compound and carbon
monoxide are copolymerized in the presence of a solvent in which
said catalyst is dissolved or dispersed. Examples of the solvent
for polymerization include water, methanol, ethanol, propanol,
acetone, methyl ethyl ketone, diethyl ether, tetrahydrofuran, ethyl
acetate and acetonitrile.
[0056] Polymerization temperature is usually in a range of
20.degree. C. to 200.degree. C., and preferably 70.degree. C. to
150.degree. C. An (alternative) copolymer of an ethylenically
unsaturated compound and carbon monoxide used in the present
invention can be obtained by polymerization under a pressure of
1.013.times.10.sup.5 Pa to 2.026.times.10.sup.7 Pa (1 atm to 200
atm), if necessary.
[0057] It can be easily confirmed by a spectroscopic analysis
method of .sup.13C-NMR or the like whether a repeating unit derived
from an ethylenically unsaturated compound and a repeating unit
derived from carbon monoxide are substantially alternatively
arranged in this polymer.
[0058] A copolymerization ratio can be controlled, for example, by
a charge ratio of an ethylenically unsaturated compound to carbon
monoxide, and a copolymer in which the molar ratio of carbon
monoxide is in a range of 1 to 50% can be usually obtained. In
order to obtain higher ionic conductivity, the molar ratio of
carbon monoxide is preferably 5 to 50% and more preferably 10 to
50%.
[0059] A weight average molecular weight of an (alternative)
copolymer of an ethylenically unsaturated compound and carbon
monoxide is preferably 5,000 to 1,000,000, and more preferably
10,000 to 1,000,000.
[0060] The (alternative) copolymer of an ethylenically unsaturated
compound and carbon monoxide of the present invention may be used
singly, but a polymer electrolyte may be produced by mixing other
polymer materials. When other polymer materials are mixed for use,
66.7 to 100% by weight of the (alternative) copolymer in the total
weight of the polymer materials is preferred, because the resulting
polymer electrolyte has high ionic conductivity. By using the
alternative copolymer mixed with other polymer materials within a
scope of the present invention, function effects such as
improvements of mechanical strength, flexibility, moldability and
chemical resistance can be obtained without impairing ionic
conductivity.
[0061] Polymer materials to be mixed may be appropriately selected,
according to the purpose, from the groups of polymer materials such
as vinyl polymerization-, ring-opening polymerization-,
condensation polymerization-, addition polymerization- and addition
condensation-materials. Examples thereof include the following
polymer materials; polyolefin-based polymers and copolymers such as
polyethylene, polypropylene and poly 4-methylpentene;
polyalkadiene-based polymers and copolymers such as polybutadiene
and polyisoprene; polyalkenyl-based polymers and copolymers such as
polystyrene and poly .alpha.-methylstyrene; vinyl ester-based
polymers and copolymers such as polyvinyl acetate and polyvinyl
butyrate; vinyl ether-based polymers and copolymers such as
poly(methyl vinyl ether) and poly(ethyl vinyl ether);
(meth)acrylate-based polymers and copolymers such as polymethyl
methacrylate and polybutyl acrylate; nitrile-based polymers and
copolymers such as polyacrylonitrile and polymethacrylonitrile;
nitrogen-containing vinyl-based polymers and copolymers such as
polyvinyl pyridine, polyvinyl imidazole, poly N-methylvinyl
pyrrolidone and polyacrylamide; fluorine-containing vinyl- and
vinylidene-based polymers and copolymers such as polyvinyl fluoride
and polyvinylidene fluoride; polyether-based polymers and
copolymers such as polyethylene oxide and polypropylene oxide;
polyimine-based polymers and copolymers such as polyethylene imine
and polypropylene imine; polythio ether-based polymers and
copolymers such as polyethylene sulfide; polyamide-based polymers
and copolymers such as nylon 6 and nylon 66; polyester-based
ring-opening polymerization type and other polyurethane-based
polymers and copolymers such as polyethylene terephthalate and
polylactic acid; and polycarbonate-based polymers and
copolymers.
[0062] Preferable examples of an electrolyte salt used as the
polymer electrolyte of the present invention include inorganic
salts such as LiClO.sub.4, LiBF.sub.4, LiPF.sub.6, LiBr, LiI, LiSCN
and LiAsF.sub.6; organic sulfonates such as CH.sub.3SO.sub.3Li and
CF.sub.3SO.sub.3Li; and sulfonyl imide salts such as
(CF.sub.3SO.sub.2).sub.2NLi, (CF.sub.3CF.sub.2SO.sub.2).sub.2NLi
and (CF.sub.3SO.sub.2)(CF.sub.3CF.sub.2SO.sub.2)NLi.
[0063] As a cation species of the above-mentioned electrolyte salt,
alkali metal salts other than a Li salt, for example, salts of
alkali metals such as sodium and potassium can also be used. In
addition, cation species such as an aliphatic quaternary ammonium
salt, an imidazolium salt, a pyridinium salt and a piperidinium
salt can also be used.
[0064] The amount of the electrolyte salt is in a range of
preferably 1 to 90% by weight, and more preferably 5 to 75% by
weight based on the total of said polymer material and said
electrolyte salt.
[0065] A polymer electrolyte can be obtained by complexing the
above-mentioned polymer material and electrolyte salt, and there
have been conventionally known, for example, the following
complexation methods.
1. A method for obtaining a polymer electrolyte by dissolving a
polymer material and an electrolyte salt in a solvent in which both
of them can be dissolved, and then removing a part or all of the
solvent (Method 1) 2. A method for obtaining a polymer electrolyte
by firstly forming a polymer material into a shape such as a film
form, and then impregnating and swelling it with a solution in
which an electrolyte salt is dissolved in a solvent, and removing a
part or all of the solvent (Method 2) 3. A method for obtaining a
polymer electrolyte by melting and kneading a polymer material and
an electrolyte salt (Method 3) 4. A method for obtaining a polymer
electrolyte by dissolving an electrolyte salt in a liquid monomer
or prepolymer, and then polymerizing them (Method 4)
[0066] As a method for complexation of a polymer material and an
electrolyte salt in the present invention, among the
above-mentioned methods, Methods 1 to 3 are preferred. A
complexation method will be described below.
[0067] A solvent used for complexation by Method 1 is water and/or
a non-aqueous solvent, and examples of the non-aqueous solvent
include cyclic carbonates such as propylene carbonate, ethylene
carbonate and vinylene carbonate; linear carbonates such as diethyl
carbonate, dimethyl carbonate and ethyl methyl carbonate; cyclic
esters such as .gamma.-butyrolactone; linear esters such as ethyl
acetate and methyl acetate; ketones such as acetone and methyl
ethyl ketone; alcohols such as methanol and ethanol; ethers such as
tetrahydrofuran, 1,4-dioxane and 1,2-dimethoxy ethane; nitrites
such as acetonitrile and benzonitrile; amides such as dimethyl
formamide, dimethyl acetoamide and N-methylpyrrolidone; and
sulforanes.
[0068] Further, as a modified method of Method 1, a solution in
which an electrolyte salt is dissolved in water or an organic
solvent at a high concentration can be used, and this method is a
particularly useful when the molar ratio of carbon monoxide within
the polymer material used by the present invention is high. The
concentration of an electrolyte salt in this case is appropriately
selected, but preferably, the weight ratio of an electrolyte salt
to the total weight of the electrolyte salt and a solvent is 30% by
weight to 90% by weight, and more preferably, 50% by weight to 90%
by weight from the viewpoint of good solubility.
[0069] A polymer electrolyte of the present invention can be
obtained by forming the solution obtained by this method into an
arbitrary shape such as a sheet by a method of coating, casting,
extruding or the like, and removing a part or all of the solvent.
In addition, an electrode for an electrochemical device using a
polymer electrolyte of the present invention can be obtained by
mixing a positive electrode active material or a negative electrode
active material in this solution, forming the mixture into a sheet
shape or the like in the same manner as described above, and then
removing a part or all of the solvent.
[0070] The removal of a part or all of a solvent can be controlled
by using, for example, a hot plate, an oven and a
temperature-programmed oven in which a temperature program can be
set. Although the drying condition is different depending on the
type and the amount of the solvent to be removed a drying
temperature condition of, for example, at 50 to 250.degree. C. in
about 30 minutes to 10 hours can be preferably used. In addition,
the solvent may be dried under reduced pressure using a vacuum
dryer.
[0071] The polymer electrolyte of the present invention may be used
as the polymer electrolyte in the above-mentioned dried state, and
may be used, if necessary, after performing a crosslinking
reaction. As a crosslinking method, general methods such as
electron beam crosslinking and chemical crosslinking by ammonia, a
diamine, a radical generator and the like are used.
[0072] When complexation is performed by Method 2, the polymer
electrolyte of the present invention can be obtained by
impregnating and swelling the solution in which electrolyte salts
are dissolved in a solvent into the polymer material of the present
invention previously formed into a shape such as a film, and
removing a part or all of the solvent. The same solvent as used in
Method 1 can be used also in Method 2. In addition, an electrode
for an electrochemical device using the polymer electrolyte of the
present invention can be obtained by previously kneading and mixing
the polymer material of the present invention with a positive
electrode active material or a negative electrode active material,
forming the mixture into a shape such as a sheet, then impregnating
and swelling it with the solution in which an electrolyte salt is
dissolved in a solvent, and removing a part or all of the
solvent.
[0073] When complexation is performed by Method 3, a polymer
electrolyte can be directly obtained by melting and kneading the
polymer material and the electrolyte salt of the present invention
and forming the mixture into a shape such as a film. In addition,
an electrode for an electrochemical device using the polymer
electrolyte of the present invention can be directly obtained by
melting and kneading a positive electrode active material or a
negative electrode active material in addition to the polymer
material and the electrolyte salt of the present invention, and
forming the resulting mixture into a shape such as a film.
[0074] When a copolymer of an ethylenically unsaturated compound
and carbon monoxide used in the present invention is an alternative
copolymer, the copolymer has high crystallinity and thus has a high
melting point and is also insoluble in most solvents. Therefore,
complexation of the copolymer with an electrolyte salt was not easy
according to the above-mentioned conventional methods.
[0075] The present inventors have invented a simple production
method of a polymer electrolyte based on the fact that a solution
containing an electrolyte salt dissolved in water or an organic
solvent at a high concentration unexpectedly dissolves an
alternative copolymer of an ethylenically unsaturated compound and
carbon monoxide.
[0076] As one of the methods for obtaining the polymer electrolyte
of the present invention, as referred to as a modified method of
the Method 1, a method using a concentrated solution of an
electrolyte salt will be described below.
[0077] An alternative copolymer of an ethylenically unsaturated
compound and carbon monoxide is completely insoluble in water and a
common non-aqueous solvent, but is exceptionally soluble in a
solution in which the electrolyte salt is dissolved in either of
water, a non-aqueous solvent or a mixture thereof at a high
concentration.
[0078] The solvent used herein is water and/or a non-aqueous
solvent, and preferable examples of the non-aqueous solvent include
cyclic carbonates such as propylene carbonate, ethylene carbonate
and vinylene carbonate; linear carbonates such as diethyl
carbonate, dimethyl carbonate and ethyl methyl carbonate; cyclic
esters such as .gamma.-butyrolactone; linear esters such as ethyl
acetate and methyl acetate; ketones such as acetone and methyl
ethyl ketone; alcohols such as methanol and ethanol; ethers such as
tetrahydrofuran, 1,4-dioxane and 1,2-dimethoxy ethane; nitrites
such as acetonitrile and benzonitrile; amides such as dimethyl
formamide, dimethyl acetoamide and N-methylpyrrolidone; and
sulforanes.
[0079] The concentration of an electrolyte salt is appropriately
selected, but preferably, the weight ratio of an electrolyte salt
to the total weight of the electrolyte salt and a solvent is 30% by
weight to 90% by weight, and more preferably, 50% by weight to 90%
by weight from the viewpoint of good solubility.
[0080] An alternative copolymer of an ethylenically unsaturated
compound and carbon monoxide can be dissolved in this concentrated
solution by mixing and stirring. The temperature for dissolving the
copolymer is appropriately selected and the polymer can be
sufficiently dissolved even at room temperature, but the dissolving
speed can be increased by heating. The heating temperature is, but
not particularly limited to, in a range from room temperature to
250.degree. C., preferably from 50.degree. C. to 200.degree. C.,
and more preferably from 80.degree. C. to 150.degree. C.
[0081] A uniform transparent solution can be obtained by this
dissolving operation, and the polymer electrolyte of the present
invention can be obtained by forming this solution into an
arbitrary shape such as a sheet by a method of coating, casting,
extruding or the like, and then removing a part or all of a
solvent. In addition, an electrode for an electrochemical device
using the polymer electrolyte of the present invention can be
obtained by mixing a positive electrode active material or a
negative electrode active material in this solution, forming the
mixture into a sheet in the same manner as described above, and
then removing a part or all of a solvent.
[0082] The removal of a part or all of a solvent can be controlled
by using, for example, a hot plate, an oven and a
temperature-programmed oven in which a temperature program can be
set. Although the drying condition is different depending on the
type and the amount of the solvent to be removed, for example, a
drying temperature condition of 50 to 250.degree. C. in about 30
minutes to 10 hours can be preferably used. In addition, the
solvent may be dried under reduced pressure using a vacuum
dryer.
[0083] The polymer electrolyte of the present invention may be used
as a polymer electrolyte directly in the above-mentioned dried
state, and may be used, if necessary, after performing a
crosslinking reaction. As a crosslinking method, general methods
such as electron beam crosslinking and chemical crosslinking by
ammonia, a diamine, a radical generator and the like are used. The
polymer electrolyte of the present invention also includes those
crosslinked by said crosslinking methods.
[0084] The first embodiment of the polymer electrolyte of the
present invention includes, for example, an all solid-type polymer
electrolyte. That is, when all of a solvent is removed by the
Method 1 (including a method using a concentrated solution of an
electrolyte salt as a modified method) or 2, an all solid-type
polymer electrolyte comprising a polymer material containing an
(alternative) copolymer of an ethylenically unsaturated compound
and carbon monoxide and an electrolyte salt can be obtained. In
addition, an all solid-type polymer electrolyte can be directly
obtained by the Method 3. An amount of the solvent remaining after
drying can be determined by NMR measurement, and when the amount is
1,000 ppm or less, all of the solvent is judged as being
removed.
[0085] The all solid-type polymer electrolyte of the present
invention has a characteristic of having an extremely high ionic
conductivity, and those having ionic conductivity equivalent to
that of a liquid electrolyte have been discovered. The reason why
the all solid-type polymer electrolyte of the present invention
exhibits high ionic conductivity is not clear, but it is supposed
that a ketone carbonyl group contained in a polymer has strong
interaction with an ion.
[0086] As an all solid-type polymer electrolyte, those using, for
example, a polyethylene oxide-based polymer or a copolymer thereof
having a polyether bond have been known so far, but either of them
has ionic conductivity significantly lower that that of a liquid
electrolyte, and therefore has not reached a practical level.
[0087] As described above, the all solid-type polymer electrolyte
of the present invention contains absolutely no liquid electrolyte,
but has high ionic conductivity, and when it is used for
non-aqueous electrochemical devices such as a lithium primary
battery, a lithium ion secondary battery and a non-aqueous electric
double layer capacitor, the following effects are exerted.
1. The electrolyte exhibits high output characteristics equivalent
to that of a liquid electrolyte. 2. The electrolyte is all
solid-type one, and therefore has no concern of liquid leakage. 3.
The electrolyte contains no liquid combustible material, and
therefore has no flammability. 4. The electrolyte has sufficient
flexibility and processability, and therefore is excellent in shape
arbitrariness such as a thin film. 5. When the electrolyte is used
as a bipolar electrode in which a positive electrode active
material and a negative electrode active material are arranged on a
front surface and a rear surface of a collector, respectively,
there is absolutely no concern of an ion liquid junction between
the positive electrode and the negative electrode formed on the
front surface and the rear surface of the collector which may be
formed in a case of a liquid electrolyte, and an electrochemical
device having a high electromotive force of several ten V or more
can be easily produced.
[0088] As described above, the all solid-type polymer electrolyte
is used among the polymer electrolytes of the present invention,
and thereby reliability, safety and characteristics of the
resulting electrochemical device can be greatly improved.
[0089] A second aspect of the polymer electrolyte of the present
invention includes, for example, a gel-type polymer electrolyte.
That is, when a part of a solvent is removed in the Method 1
(including a method using a concentrated solution of an electrolyte
salt as a modified method) or 2, an apparently solid gel-type
polymer electrolyte containing an (alternative) copolymer of an
ethylenically unsaturated compound and carbon monoxide, an
electrolyte salt and a solvent can be obtained. Although a
composition ratio of a solvent to an (alternative) copolymer of an
ethylenically unsaturated compound and carbon monoxide is
appropriately selected depending on the purpose, the weight ratio
of a solvent to the total weight of the solvent and the
(alternative) copolymer is preferably less than 70% by weight, more
preferably less than 50% by weight, and most preferably less than
33.3% by weight.
[0090] Further, when 100% of the polymer material is a copolymer of
an ethylenically unsaturated compound and carbon monoxide, the
weight ratio of a solvent to the total weight of the solvent and
the copolymer is preferably less than 33.3% by weight, and more
preferably less than 20% by weight. When the weight ratio is 33.3%
by weight or more, reliability such as liquid leakage resistance is
impaired and mechanical strength as a polymer electrolyte is
decreased.
[0091] Generally, in the case of a gel-type polymer electrolyte,
when the weight ratio of a solvent to be added is large, the
resulting electrolyte has an antinomy relationship that ionic
conductivity becomes high, but reliability such as liquid leakage
resistance is impaired and mechanical strength as a polymer
electrolyte is decreased.
[0092] However, as described above, even when the polymer
electrolyte of the present invention is an all solid-type polymer
electrolyte, sufficient high ionic conductivity can be obtained.
Therefore, a gel-type polymer electrolyte remaining a part of a
solvent is used as the polymer electrolyte of the present
invention, and thereby the effect is exerted in a small amount of
solvent as compared with a conventional gel-type polymer
electrolyte even in the case of further increasing ionic
conductivity, particularly ionic conductivity in a low temperature
region, and therefore reliability such as liquid leakage resistance
is hardly impaired.
[0093] The gel-type polymer electrolyte of the present invention
will be further described.
[0094] An aqueous gel-type polymer electrolyte obtained when a
solvent is water in the present invention substantially maintains
high intrinsic ionic conductivity of an aqueous electrolyte
solution. Accordingly, when the electrolyte is used for aqueous
electrochemical devices such as an aqueous ion battery and an
aqueous electric double layer capacitor, it causes no reduction in
output characteristics, low temperature characteristics and the
like, and provides significantly improved reliability, and
therefore is useful.
[0095] Further, a non-aqueous gel-type polymer electrolyte obtained
when a solvent is a non-aqueous solvent substantially maintains
ionic conductivity of a non-aqueous electrolyte solution and
maintains high ionic conductivity particularly in a low temperature
region. Therefore, it is useful for non-aqueous electrochemical
devices such as a dye-sensitized solar cell and an electrochromic
device in addition to a lithium primary battery, a lithium ion
secondary battery and a non-aqueous electric double layer
capacitor.
[0096] As described above, a polymer electrolyte having a high
ionic conductivity can be provided by using the (alternative)
copolymer of an ethylenically unsaturated compound and carbon
monoxide of the present invention, and can be used for various
electrochemical devices as an all solid-type polymer electrolyte or
gel-type polymer electrolyte depending on the purpose. Herein, the
term "electrochemical device" is referred to as a device applying
an electrochemical phenomenon involving an ion, and specific
examples thereof include devices such as a storage device, a power
generation device, a display device and a sensor device.
[0097] In the present invention, a polymer electrolyte may be a
self-supporting film or a non-self-supporting film, and can be used
without particular problems even if exudation of liquid is
observed, but it is preferred that the electrolyte is a
self-supporting film and no exudation of liquid is observed.
[0098] An example of an electrochemical device using the polymer
electrolyte of the present invention will be described below.
[0099] FIG. 1 is a plan view and a longitudinal sectional view
showing an example of an electrochemical device of the present
invention. In FIG. 1, 1 indicates a positive electrode; 2 indicates
a negative electrode; 3 indicates a positive electrode lead
terminal; 4 indicates a negative electrode lead terminal; 5
indicates a polymer electrolyte; and 6 indicates a battery
container.
[0100] Specific examples of the electrochemical device include a
lithium primary battery using metal lithium as a negative electrode
and using manganese dioxide, carbon fluoride or the like as a
positive electrode; a lithium ion secondary battery using a carbon
material, a metal oxide, a lithium alloy or the like as a negative
electrode and using lithium cobaltate, lithium nickelate, lithium
manganate, lithium iron phosphate or the like as a positive
electrode; and an electric double layer capacitor using active
carbon as a positive electrode and a negative electrode; and an
aqueous ion battery using a lithium-transition metal composite
oxide of vanadium, titanium, iron or the like as a negative
electrode and using a lithium-transition metal composite oxide of
cobalt, manganese, iron or the like as a positive electrode.
EXAMPLES
[0101] Hereinafter, the present invention will be specifically
described by way of Examples and Comparative Examples.
Reference Example 1
Production of Polymer A
[0102] Into a 1 L-volume SUS autoclave with a stirrer, 800 ml of
dimethyl carbonate as a polymerization solvent and 1.2 g of
azobisisovaleronitrile as a polymerization initiator were charged,
and subsequently a mixed gas having a pressure ratio of ethylene to
carbon monoxide of 1 was charged so as to give a pressure of 4.5
MPa at room temperature. The temperature of the autoclave was
raised to 60.degree. C. while stirring. The mixture was reacted for
6 hours while adding the mixed gas so as to keep the pressure at 5
MPa. After cooling, the reactant is removed and the solid content
was washed to obtain a white powder.
[0103] It was confirmed from .sup.13C-NMR and an infrared
absorption spectrum that this polymer was a product obtained by
polymerizing ethylene and carbon monoxide (hereinafter, referred to
as "Polymer A"), and the molar ratio of carbon monoxide was 43.2%.
In addition, this Polymer A had a weight average molecular weight
of 85,000.
Reference Example 2
Production of Polymer B
[0104] Completely the same operation as in Reference Example 1 was
performed except that the pressure ratio of ethylene to carbon
monoxide was changed to 2 in Reference Example 1. After cooling,
the reactant was removed and the solid content was washed to obtain
a white powder.
[0105] It was confirmed from .sup.13C-NMR and an infrared
absorption spectrum that this polymer was a product obtained by
polymerizing ethylene and carbon monoxide (hereinafter, referred to
as "Polymer B"), and the molar ratio of carbon monoxide was 21.3%.
In addition, this Polymer B had a weight average molecular weight
of 56,000.
Reference Example 3
Production of Polymer C
[0106] Completely the same operation as in Reference Example 1 was
performed except that the pressure ratio of ethylene to carbon
monoxide was changed to 10 in Reference Example 1. After cooling,
the reactant was removed and the solid content was washed to obtain
a white powder.
[0107] It was confirmed from .sup.13C-NMR and an infrared
absorption spectrum that this polymer was a product obtained by
polymerizing ethylene and carbon monoxide (hereinafter, referred to
as "Polymer C"), and the molar ratio of carbon monoxide was 10.9%.
In addition, this Polymer C had a weight average molecular weight
of 72,000.
Example 1
[0108] 50 parts by weight of lithium
bis(trifluoromethanesulfonyl)imide {(CF.sub.3SO.sub.2).sub.2NLi} as
an electrolyte salt was mixed with and dissolved in 50 parts by
weight of water to make a solution having a concentration of 50% by
weight. 100 parts by weight of this solution and 85 parts by weight
of Polymer A were charged into an autoclave, and the mixture was
heated and stirred at 120.degree. C. to obtain a transparent
viscous solution.
[0109] After 0.1 parts by weight of hexamethylenediamine as a
crosslinking agent was added to 100 parts by weight of this viscous
solution, the mixture was cast to a thickness of 500 .mu.m on a
glass plate. Thereafter, the cast mixture was dried under
atmospheric pressure at 80.degree. C. for 1 hour to thereby obtain
a non-sticky gel-type polymer electrolyte in a film form.
[0110] The weight ratio of water to the total of Polymer A and
water determined by .sup.1HNMR at this time point was 21.9% by
weight. Here, the NMR measurement was performed using JNM-LA400
manufactured by JEOL Ltd. The ionic conductivity of this gel-type
polymer electrolyte was measured at 30.degree. C. and 0.degree. C.
in an alternating current of 1 KHz. The results are shown in Table
1.
Example 2
[0111] The same operation as in Example 1 was performed except that
85 parts by weight of Polymer A was replaced with a mixture of 75
parts by weight of Polymer A and 10 parts by weight of a
polyether-based copolymer of ethylene oxide and
2-(2-methoxyethoxyethyl)glycidyl ether having a weight average
molecular weight of 14,000 (copolymerization ratio=73:27,
hereinafter referred to as "Polymer D") in Example 1. As a result,
a non-sticky gel-type polymer electrolyte in a film form was
obtained.
[0112] The weight ratio of water to the total of Polymer A, Polymer
D and water was 22.5% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 1.
Example 3
[0113] The same operation as in Example 1 was performed except that
85 parts by weight of Polymer A was replaced with a mixture of 68
parts by weight of Polymer A and 17 parts by weight of Polymer D in
Example 1. As a result, a non-sticky gel-type polymer electrolyte
in a film form was obtained.
[0114] The weight ratio of water to the total of Polymer A, Polymer
D and water was 23.3% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 1.
Example 4
[0115] The same operation as in Example 1 was performed except that
85 parts by weight of Polymer A was replaced with a mixture of 62
parts by weight of Polymer A and 23 parts by weight of Polymer D in
Example 1. As a result, a non-sticky gel-type polymer electrolyte
in a film form was obtained.
[0116] The weight ratio of water to the total of Polymer A, Polymer
D and water was 24.5% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 1.
Example 5
[0117] The same operation as in Example 1 was performed except that
85 parts by weight of Polymer A was replaced with a mixture of 58
parts by weight of Polymer A and 27 parts by weight of Polymer D in
Example 1. As a result, a non-sticky gel-type polymer electrolyte
in a film form was obtained.
[0118] The weight ratio of water to the total of Polymer A, Polymer
D and water was 21.9% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 1.
Comparative Example 1
[0119] The same operation as in Example 1 was performed except that
85 parts by weight of Polymer A was replaced with a mixture of 55
parts by weight of Polymer A and 30 parts by weight of Polymer D in
Example 1. As a result, a slightly sticky gel-type polymer
electrolyte in a film form was obtained.
[0120] The weight ratio of water to the total of Polymer A, Polymer
D and water was 23.3% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 1.
Comparative Example 2
[0121] The same operation as in Example 1 was performed except that
85 parts by weight of Polymer A was replaced with a mixture of 35
parts by weight of Polymer A and 50 parts by weight of Polymer D in
Example 1. As a result, a highly sticky gel-type polymer
electrolyte in a film form was obtained.
[0122] The weight ratio of water to the total of Polymer A, Polymer
D and water was 21.6% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 1.
Comparative Example 3
[0123] The same operation as in Example 1 was performed except that
85 parts by weight of Polymer A was replaced with 85 parts by
weight of Polymer D in Example 1 and hexamethylenediamine was not
used. As a result, a highly sticky gel-type polymer electrolyte in
a film form was obtained.
[0124] The weight ratio of water to the total of Polymer D and
water was 20.5% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 1.
[0125] [Table 1]
TABLE-US-00001 TABLE 1 Content of carbon oxide Ionic copolymer
conductivity in polymer (mScm.sup.-1) Properties of material Upper
row: 30.degree. C. polymer (% by weight) Lower row: 0.degree. C.
electrolyte Example 1 100 9.5 Self-supporting 6.3 film causing no
exudation of liquid Example 2 88.2 9.0 Self-supporting 5.7 film
causing no exudation of liquid Example 3 80.0 7.9 Self-supporting
4.9 film causing no exudation of liquid Example 4 72.9 7.2
Self-supporting 4.5 film causing no exudation of liquid Example 5
68.2 6.1 Self-supporting 3.9 film causing no exudation of liquid
Comparative 64.7 1.1 Self-supporting Example 1 0.9 film having
slight stickiness in which exudation of liquid was observed
Comparative 41.2 0.8 Non-self- Example 2 0.5 supporting film having
high stickiness in which exudation of liquid was observed
Comparative 0 0.2 Non-self- Example 3 0.1 supporting film having
high stickiness in which exudation of liquid was observed
Example 6
[0126] 30 parts by weight of lithium boron tetrafluoride
(LiBF.sub.4) as an electrolyte salt was mixed with and dissolved in
70 parts by weight of .gamma.-butyrolactone to make a solution
having a concentration of 30% by weight. 100 parts by weight of
this solution and 120 parts by weight of Polymer B were charged
into an autoclave and the mixture was heated and stirred at
120.degree. C. to obtain a transparent viscous solution.
[0127] After this viscous solution was cast to a thickness of 500
.mu.m on a glass plate, the cast solution was dried under
atmospheric pressure at 120.degree. C. for 1 hour. Thereafter, the
glass plate was placed in a vacuum dryer set at 150.degree. C. and
further dried for 10 hours. As a result, an all solid-type polymer
electrolyte in a film form having a .gamma.-butyrolactone content
of 1,000 ppm or less determined by .sup.13CNMR measurement was
obtained.
[0128] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. in an alternating current
of 1 KHz. The result is shown in Table 2.
Example 7
[0129] The same operation as in Example 6 was performed except that
120 parts by weight of Polymer B was replaced with a mixture of 100
parts by weight of Polymer B and 20 parts by weight of a copolymer
of vinylidene fluoride and hexafluoropropylene having a weight
average molecular weight of 35,000 (copolymerization ratio=88:12,
hereinafter referred to as "Polymer E") in Example 6. As a result,
an all solid-type polymer electrolyte in a film form having a
.gamma.-butyrolactone content of 1,000 ppm or less determined by
.sup.13CNMR measurement was obtained.
[0130] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. in an alternating current
of 1 KHz. The result is shown in Table 2.
Example 8
[0131] The same operation as in Example 6 was performed except that
120 parts by weight of Polymer B was replaced with a mixture of 85
parts by weight of Polymer B and 35 parts by weight of Polymer E in
Example 6. As a result, an all solid-type polymer electrolyte in a
film form having a .gamma.-butyrolactone content of 1,000 ppm or
less determined by .sup.13CNMR measurement was obtained.
[0132] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. in an alternating current
of 1 KHz. The result is shown in Table 2.
Comparative Example 4
[0133] The same operation as in Example 6 was performed except that
120 parts by weight of Polymer B was replaced with a mixture of 75
parts by weight of Polymer B and 45 parts by weight of Polymer E in
Example 6. As a result, an all solid-type polymer electrolyte in a
film form having a .gamma.-butyrolactone content of 1,000 ppm or
less determined by .sup.13CNMR measurement was obtained.
[0134] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. in an alternating current
of 1 KHz. The result is shown in Table 2.
Comparative Example 5
[0135] The same operation as in Example 6 was performed except that
120 parts by weight of Polymer B was replaced with a mixture of 45
parts by weight of Polymer B and 75 parts by weight of Polymer E in
Example 6. As a result, an all solid-type polymer electrolyte in a
film form having a .gamma.-butyrolactone content of 1,000 ppm or
less determined by .sup.13CNMR measurement was obtained.
[0136] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. in an alternating current
of 1 KHz. The result is shown in Table 2.
Comparative Example 6
[0137] The same operation as in Example 6 was performed except that
120 parts by weight of Polymer B was replaced with 120 parts by
weight of Polymer E in Example 6. As a result, a film could not be
obtained, but a white powder mixture was obtained.
[0138] The content of propylene carbonate in this
[0139] Polymer E determined by .sup.13CNMR measurement was 1,000
ppm or less, but it was impossible to measure the ionic
conductivity.
[0140] [Table 2]
TABLE-US-00002 TABLE 2 Content of carbon oxide Ionic copolymer
conductivity in polymer (mScm.sup.-1) Properties of material Upper
row: 30.degree. C. polymer (% by weight) Lower row: 0.degree. C.
electrolyte Example 6 100 2.1 Self-supporting 1.6 film causing no
exudation of liquid Example 7 83.3 1.9 Self-supporting 1.2 film
causing no exudation of liquid Example 8 70.8 1.2 Self-supporting
0.9 film causing no exudation of liquid Comparative 62.5 0.2
Brittle film Example 4 0.1 Comparative 37.5 0.09 Brittle film
Example 5 0.03 Comparative 0 Unmeasurable Powder form Example 6
Unmeasurable
Example 9
[0141] After 75 parts by weight of Polymer A and 25 parts by weight
of Polymer E were melted and kneaded, the mixture was formed into a
film having a thickness of 150.mu.. This film was irradiated with
electron rays with a dose of 5.0 Mrad to obtain a crosslinked
film.
[0142] This film was immersed in a solution having a concentration
of 20% by weight in which 20 parts by weight of lithium boron
tetrafluoride (LiBF.sub.4) mixed with and dissolved in 80 parts by
weight of .gamma.-butyrolactone, at 120.degree. C. for 2 hours, and
thereafter the film was cooled to room temperature and the surface
of the film was washed. The film was swollen and the weight was
increased by 85% based on the original weight.
[0143] The properties of composition, ionic conductivity and
polymer electrolyte of this film were as shown in Table 3.
Example 10
[0144] The same operation as in Example 9 was performed except that
the mixed ratio of polymers was changed to that of 68 parts by
weight of Polymer A and 32 parts by weight of Polymer E in Example
9. As a result, a swollen film increased in weight by 215% based on
the original weight was obtained.
[0145] The properties of composition, ionic conductivity and
polymer electrolyte of this film were as shown in Table 3.
[0146] [Table 3]
TABLE-US-00003 TABLE 3 Weight of solvent/ Ionic (Weight of
conductivity solvent and (mScm.sup.-1) Properties of high polymer)
Upper row: 30.degree. C. polymer (% by weight) Lower row: 0.degree.
C. electrolyte Example 9 40.5 5.3 Self-supporting 3.2 film causing
no exudation of liquid Example 10 63.2 6.7 Self-supporting 4.1 film
causing no exudation of liquid
Example 11
[0147] The present example shows an example of an electrochemical
device of the present invention using a gel-type polymer
electrolyte of the present invention.
[0148] FIG. 1 is a schematic cross-sectional view of this
electrochemical device.
[0149] <Preparation of Polymer Electrolyte Solution (1)>
[0150] Lithium boron tetrafluoride (LiBF.sub.4), propylene
carbonate and Polymer A were charged at a weight ratio of
20:70:100, and the mixture was heated and stirred at 120.degree. C.
to obtain a viscous solution.
[0151] <Preparation of Positive Electrode Sheet>
[0152] LiCoO.sub.2 (average particle size: 5 .mu.m) as a positive
electrode active material, and graphite and acetylene black as
conductive auxiliaries were dry-mixed at a weight ratio of
100:5:2.5.
[0153] After 100 parts by weight of a polymer electrolyte solution
(1) and 100 parts by weight of the mixture of a positive electrode
active material and conductive auxiliaries were kneaded to be made
in a paste form, the mixture was applied to one surface of an
aluminum foil positive electrode collector having a thickness of 15
.mu.m at a thickness of 200 .mu.m. The collector was dried at
150.degree. C. for 2 hours to obtain a positive electrode
sheet.
[0154] The content of propylene carbonate contained in this
positive electrode sheet was 12.3% by weight based on the total
weight of the positive electrode sheet excluding an aluminum foil
positive electrode collector.
[0155] <Preparation of Negative Electrode Sheet>
[0156] After 50 parts by weight of graphite (average particle size:
10 .mu.m) as a negative electrode active material was kneaded with
100 parts by weight of a polymer electrolyte solution (1) to be
made in a paste form, the mixture was applied to one surface of a
copper foil negative electrode collector having a thickness of 18
.mu.m at a thickness of 150 .mu.m. The collector was dried at
150.degree. C. for 2 hours to obtain a negative electrode
sheet.
[0157] The content of propylene carbonate contained in this
negative electrode sheet was 14.4% by weight based on the total
weight of the negative electrode sheet excluding a copper foil
negative electrode collector.
[0158] <Preparation of Electrochemical Device>
[0159] Polymer C was press-molded at 210.degree. C. to prepare a
film having a thickness of 18 .mu.m. This film was immersed in a
solution in which the weight ratio of lithium boron tetrafluoride
(LiBF.sub.4) to propylene carbonate is 40:60. The film was left
standing at room temperature for 24 hours, and thereby swollen and
a polymer electrolyte film increased in weight by 48.3% based on
the original weight was obtained.
[0160] The positive electrode sheet and the negative electrode
sheet were laminated interposing this polymer electrolyte film
therebetween to assemble an electrochemical device shown in FIG.
1.
[0161] <Property Evaluation of Electrochemical Device>
[0162] The evaluation of charge and discharge properties of this
electrochemical device was performed as follows. After charging in
a constant-current/constant-voltage charging mode of a maximum
current of 50 mA and a maximum voltage of 4.2 V for 5 hours, the
electrochemical device was discharged to 3.0 V at a constant
current of 10 mA. The discharge volume was 86.2 mAh. Thereafter,
the electrochemical device was recharged in the same condition, and
the evaluation of discharge volume was performed under a constant
current condition shown in Table 4. The results are shown in Table
4.
Example 12
Preparation of Polymer Electrolyte Solution (2)
[0163] Lithium boron tetrafluoride (LiBF.sub.4), polypropylene
carbonate, Polymer A and Polymer E were charged at a weight ratio
of 20:70:75:25, and the mixture was heated and stirred at
120.degree. C. to obtain a viscous solution.
[0164] <Preparation of Positive Electrode Sheet>
[0165] A positive electrode sheet was obtained in the same manner
as in Example 11 except for using the Polymer Electrolyte Solution
(2).
[0166] The content of propylene carbonate contained in this
positive electrode sheet was 11.9% by weight based on the total
weight of the positive electrode sheet excluding an aluminum foil
positive electrode collector.
[0167] <Preparation of Negative Electrode Sheet>
[0168] A negative electrode sheet was obtained in the same manner
as in Example 11 except for using the Polymer Electrolyte Solution
(2).
[0169] The content of propylene carbonate contained in this
negative electrode sheet was 14.9% by weight based on the total
weight of the negative electrode sheet excluding a copper foil
negative electrode collector.
[0170] <Preparation of Electrochemical Device>
[0171] A polymer electrolyte film increased in weight by 39.5% by
weight based on the original weight was obtained in the same manner
as in Example 11 was performed except that a mixture having a
weight ratio of Polymer C to Polymer E of 75:25 was used as a film
material.
[0172] The positive electrode sheet and the negative electrode
sheet were laminated interposing this polymer electrolyte film
therebetween to assemble an electrochemical device shown in FIG.
1.
[0173] <Property Evaluation of Electrochemical Device>
[0174] The evaluation of charge and discharge properties of this
electrochemical device was performed in the same manner as in
Example 11. The results are shown in Table 4.
Comparative Example 7
Preparation of Polymer Electrolyte Solution (3)
[0175] Lithium boron tetrafluoride (LiBF.sub.4), propylene
carbonate, Polymer A and Polymer E were charged at a weight ratio
of 20:70:60:40, and the mixture was heated and stirred at
120.degree. C. to obtain a viscous solution.
[0176] <Preparation of Positive Electrode Sheet>
[0177] A positive electrode sheet was obtained in the same manner
as in Example 11 except for using the Polymer Electrolyte Solution
(3).
[0178] The content of propylene carbonate contained in this
positive electrode sheet was 12.6% by weight based on the total
weight of the positive electrode sheet excluding an aluminum foil
positive electrode collector.
[0179] <Preparation of Negative Electrode Sheet>
[0180] A negative electrode sheet was obtained in the same manner
as in Example 11 except for using the Polymer Electrolyte Solution
(3).
[0181] The content of propylene carbonate contained in this
negative electrode sheet was 15.8% by weight based on the total
weight of the negative electrode sheet excluding a copper foil
negative electrode collector.
[0182] <Preparation of Electrochemical Device>
[0183] A polymer electrolyte film increased in weight by 33.9% by
weight based on the original weight was obtained in the same manner
as in Example 11 was performed except that a mixture having a
weight ratio of Polymer C to Polymer E of 60:40 was used as a film
material.
[0184] The positive electrode sheet and the negative electrode
sheet were laminated interposing this polymer electrolyte film
therebetween to assemble an electrochemical device shown in FIG.
1.
[0185] <Property Evaluation of Electrochemical Device>
[0186] The evaluation of charge and discharge properties of this
electrochemical device was performed in the same manner as in
Example 11. The results are shown in Table 4.
[0187] [Table 4]
TABLE-US-00004 TABLE 4 Content of carbon oxide copolymer in polymer
Discharge condition (mA) and material discharge volume (mAh) (% by
weight) 10 mA 50 mA 100 mA Example 11 100 86.2 mAh 80.6 mAh 76.7
mAh Example 12 75.0 80.1 mAh 75.3 mAh 69.6 mAh Comparative 60.0
24.9 mAh 9.1 mAh Non- Example 7 dischargeable
Example 13
[0188] 50 parts by weight of lithium
bis(trifluoromethanesulfonyl)imide {(CF.sub.3SO.sub.2).sub.2NLi} as
an electrolyte salt was mixed with and dissolved in 50 parts by
weight of water to make a solution having a concentration of 50% by
weight. 100 parts by weight of this solution and 75 parts by weight
of Polymer A were charged into an autoclave and the mixture was
heated and stirred at 120.degree. C. to obtain a transparent
viscous solution.
[0189] After 0.1 parts by weight of hexamethylenediamine as a
crosslinking agent was added to 100 parts by weight of this viscous
solution, the mixture was cast to a thickness of 500 .mu.m on a
glass plate. Thereafter, the cast mixture was dried under
atmospheric pressure at 80.degree. C. for 1 hour to thereby obtain
a slightly sticky gel-type polymer electrolyte in a film form.
[0190] The weight ratio of water to the total of Polymer A and
water determined by .sup.1HNMR measurement at this time point was
32.1% by weight. Here, the NMR measurement was performed using
JNM-LA400 manufactured by JEOL Ltd. The ionic conductivity of this
gel-type polymer electrolyte was measured at 30.degree. C. and
0.degree. C. in an alternating current of 1 KHz. The results are
shown in Table 5.
Example 14
[0191] The same operation as in Example 13 was performed except
that the drying hour at 80.degree. C. was changed to 3 hours in
Example 13. As a result, a substantially non-sticky gel-type
polymer electrolyte in a film form was obtained.
[0192] The weight ratio of water to the total of a polymer of
ethylene and carbon monoxide and water was 19.3% by weight at this
time point. The ionic conductivity of this gel-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 5.
Example 15
[0193] The same operation as in Example 13 was performed except
that the drying hour at 80.degree. C. was changed to 6 hours in
Example 13. As a result, an absolutely non-sticky gel-type polymer
electrolyte in a film form was obtained.
[0194] The weight ratio of water to the total of a polymer of
ethylene and carbon monoxide and water was 9.2% by weight at this
time point. The ionic conductivity of this gel-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 5.
Example 16
[0195] After a viscous solution obtained in the same manner as in
Example 13 was cast to a thickness of 500 .mu.m on a glass plate,
the cast solution was dried under atmospheric pressure at
120.degree. C. for 3 hour. Thereafter, the glass plate was placed
in a vacuum dryer set at 150.degree. C. and further dried for 10
hours. As a result, an all solid-type polymer electrolyte in a film
form having a water content of 1,000 ppm or less determined by
.sup.1HNMR measurement was obtained.
[0196] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 5.
Example 17
[0197] The same operation as in Example 13 was performed except
that the drying hour at 80.degree. C. was changed to 0.5 hours in
Example 13. As a result, a highly sticky and non-self-supporting
gel-type polymer electrolyte was obtained.
[0198] The weight ratio of water to the total of a polymer of
ethylene and carbon monoxide and water was 35.7% by weight at this
time point. The ionic conductivity of this gel-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 5.
[0199] [Table 5]
TABLE-US-00005 TABLE 5 (Weight of solvent)/ Ionic (Weight of
conductivity solvent and (mScm.sup.-1) Properties of high polymer)
Upper row: 30.degree. C. polymer (% by weight) Lower row: 0.degree.
C. electrolyte Example 13 32.1 10.3 Self-supporting 7.1 film having
slight stickiness but causing no exudation of liquid Example 14
19.3 8.1 Self-supporting 5.2 film causing no exudation of liquid
Example 15 8.9 6.9 Self-supporting 3.9 film causing no exudation of
liquid Example 16 0 4.1 Self-supporting 1.2 film causing no
exudation of liquid Example 17 35.7 10.1 Non-self- 6.9 supporting
film having high stickiness in which exudation of liquid was
observed
Example 18
[0200] 30 parts by weight of lithium boron tetrafluoride
(LiBF.sub.4) as an electrolyte salt was mixed with and dissolved in
70 parts by weight of .gamma.-butyrolactone to make a solution
having a concentration of 30% by weight (hereinafter, referred to
as "Solution A"). 100 parts by weight of this solution and 95 parts
by weight of Polymer B were charged and the mixture was heated and
stirred at 120.degree. C. to obtain a transparent viscous
solution.
[0201] After this viscous solution was cast to a thickness of 500
.mu.m on a glass plate, the cast solution was dried under
atmospheric pressure at 120.degree. C. for 2 hours. As a result, a
slightly sticky gel-type polymer electrolyte in a film form was
obtained.
[0202] The weight ratio of .gamma.-butyrolactone to the total of a
polymer of ethylene and carbon monoxide and .gamma.-butyrolactone
determined by .sup.13CNMR measurement was 31.9% by weight at this
time point. The ionic conductivity of this gel-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 6.
Example 19
[0203] The same operation as in Example 18 was performed except
that the drying condition was changed to drying at 120.degree. C.
for 3 hours in Example 18. As a result, a substantially non-sticky
gel-type polymer electrolyte in a film form was obtained.
[0204] The weight ratio of .gamma.-butyrolactone to the total of a
polymer of ethylene and carbon monoxide and .gamma.-butyrolactone
was 18.3% by weight at this time point. The ionic conductivity of
this gel-type polymer electrolyte was measured at 30.degree. C. and
0.degree. C. in an alternating current of 1 KHz. The results are
shown in Table 6.
Example 20
[0205] The same operation as in Example 18 was performed except
that the drying condition was changed to drying at 120.degree. C.
for 6 hours in Example 18. As a result, an absolutely non-sticky
gel-type polymer electrolyte in a film form was obtained.
[0206] The weight ratio of .gamma.-butyrolactone to the total of a
polymer of ethylene and carbon monoxide and .gamma.-butyrolactone
was 7.2% by weight at this time point.
[0207] The ionic conductivity of this gel-type polymer electrolyte
was measured at 30.degree. C. and 0.degree. C. in an alternating
current of 1 KHz. The results are shown in Table 6.
Example 21
[0208] 100 parts by weight of Solution A obtained in the same
manner as in Example 18 and 95 parts by weight of Polymer B were
charged into an autoclave, and the mixture was heated and stirred
at 120.degree. C. to obtain a transparent viscous solution.
[0209] After this viscous solution was cast to a thickness of 500
.mu.m on a glass plate, the cast solution was dried under
atmospheric pressure at 120.degree. C. for 1 hour. Thereafter, the
glass plate was placed in a vacuum dryer set at 150.degree. C. and
further dried for 10 hours. As a result, an all solid-type polymer
electrolyte in a film form having a .gamma.-butyrolactone content
of 1,000 ppm or less determined by .sup.13CNMR measurement was
obtained.
[0210] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. in an alternating current
of 1 KHz. The result is shown in Table 6.
Example 22
[0211] The same operation as in Example 18 was performed except
that the drying condition was changed to drying at 120.degree. C.
for 1 hour in Example 18. As a result, a highly sticky and
non-self-supporting gel-type polymer electrolyte was obtained.
[0212] The weight ratio of .gamma.-butyrolactone to the total of a
polymer of ethylene and carbon monoxide and .gamma.-butyrolactone
was 41.3% by weight at this time point. The ionic conductivity of
this gel-type polymer electrolyte was measured at 30.degree. C. and
0.degree. C. in an alternating current of 1 KHz. The results are
shown in Table 6.
[0213] [Table 6]
TABLE-US-00006 TABLE 6 (Weight of solvent)/ Ionic (Weight of
conductivity solvent and (mScm.sup.-1) Properties of high polymer)
Upper row: 30.degree. C. polymer (% by weight) Lower row: 0.degree.
C. electrolyte Example 18 31.9 2.6 Self-supporting 2.1 film having
slight stickiness but causing no exudation of liquid Example 19
18.3 2.1 Self-supporting 1.8 film causing no exudation of liquid
Example 20 7.2 1.9 Self-supporting 1.1 film causing no exudation of
liquid Example 21 0 1.3 Self-supporting 0.5 film causing no
exudation of liquid Example 22 41.3 2.7 Non-Self- 2.2 supporting
film having high stickiness in which exudation of liquid was
observed
Comparative Example 8
[0214] 100 parts by weight of Polymer E, 25 parts by weight of
lithium bis(trifluoromethanesulfonyl)imide
{(CF.sub.3SO.sub.2).sub.2NLi} as an electrolyte salt and 120 parts
by weight of propylene carbonate were mixed with and dissolved in
200 parts by weight of dimethylformamide at 60.degree. C.
[0215] After this solution was cast to a thickness of 500 .mu.m on
a glass plate, the cast solution was dried under atmospheric
pressure at 120.degree. C. for 2 hours. As a result, a slightly
sticky gel-type polymer electrolyte in a film form was
obtained.
[0216] The weight ratio of propylene carbonate to the total weight
of Polymer E and propylene carbonate was 45.3% by weight at this
time point, and dimethylformamide was not remained. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 7.
Comparative Example 9
[0217] The same operation as in Comparative Example 8 was performed
except that the drying condition was changed to drying at
150.degree. C. for 3 hours in Comparative Example 8. As a result, a
substantially non-sticky gel-type polymer electrolyte in a film
form was obtained.
[0218] The weight ratio of propylene carbonate to the total weight
of Polymer E and propylene carbonate was 24.8% by weight at this
time point. The ionic conductivity of this gel-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 7.
Comparative Example 10
[0219] The same operation as in Comparative Example 8 was performed
except that the drying condition was changed to drying at
150.degree. C. for 6 hours in Comparative Example 8. As a result, a
very brittle gel-type polymer electrolyte in a film form was
obtained.
[0220] The weight ratio of propylene carbonate to the total weight
of Polymer E and propylene carbonate was 16.8% by weight at this
time point. The ionic conductivity of this gel-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 7.
Comparative Example 11
[0221] After the solution containing Polymer E and the electrolyte
salt obtained in the same manner as in Comparative Example 8 was
cast to a thickness of 500 .mu.m on a glass plate, the cast
solution was dried under atmospheric pressure at 120.degree. C. for
2 hours. Thereafter, the glass plate was placed in a vacuum dryer
set at 150.degree. C. and further dried for 10 hours. As a result,
a film could not be obtained, but a white powder mixture was
obtained.
[0222] The content of propylene carbonate in this mixture was 1,000
ppm or less, but it was impossible to measure the ionic
conductivity.
Comparative Example 12
[0223] 100 parts by weight of Polymer D and 25 parts by weight of
lithium bis(trifluoromethanesulfonyl)imide
{(CF.sub.3SO.sub.2).sub.2NLi} as an electrolyte salt were mixed
with and dissolved in 250 parts by weight of acetonitrile.
[0224] After this solution was cast to a thickness of 500 .mu.m on
a glass plate, the cast solution was dried under atmospheric
pressure at 80.degree. C. for 2 hours. As a result, an all
solid-type polymer electrolyte in a film form in which acetonitrile
was completely volatilized was obtained.
[0225] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 7.
[0226] [Table 7]
TABLE-US-00007 TABLE 7 (Weight of solvent)/ Ionic (Weight of
conductivity solvent and (mScm.sup.-1) Properties of high polymer)
Upper row: 30.degree. C. polymer (% by weight) Lower row: 0.degree.
C. electrolyte Comparative 45.3 0.93 Non-self- Example 8 0.29
supporting film having high stickiness in which exudation of liquid
was observed Comparative 24.8 0.39 Self-supporting Example 9 0.13
film having slight stickiness in which exudation of liquid was
observed Comparative 16.8 0.09 Brittle film Example 10 0.01
Comparative 0 Unmeasurable Powder form Example 11 Unmeasurable
Comparative 0 0.11 Self-supporting Example 12 0.03 film
Example 23
[0227] The present example shows an example of an electrochemical
device of the present invention using a gel-type polymer
electrolyte of the present invention. FIG. 1 is a schematic
cross-sectional view of this electrochemical device.
[0228] <Preparation of Polymer Electrolyte Solution (4)>
[0229] Lithium boron tetrafluoride (LiBF.sub.4), polypropylene
carbonate and Polymer A were charged at a weight ratio of
20:80:100, and the mixture was heated and stirred at 120.degree. C.
to obtain a viscous solution.
[0230] <Preparation of Positive Electrode Sheet>
[0231] LiCoO.sub.2 (average particle size: 5 .mu.m) as a positive
electrode active material, and graphite and acetylene black as
conductive auxiliaries were dry-mixed at a weight ratio of
100:5:2.5.
[0232] After 100 parts by weight of a polymer electrolyte solution
(4) and 100 parts by weight of the mixture of a positive electrode
active material and conductive auxiliaries were kneaded to be made
in a paste form, the mixture was applied to one surface of an
aluminum foil positive electrode collector having a thickness of 15
.mu.m at a thickness of 200 .mu.m. The collector was dried at
150.degree. C. for 2 hours to obtain a positive electrode
sheet.
[0233] The content of propylene carbonate contained in this
positive electrode sheet was 11.8% by weight based on the total
weight of the positive electrode sheet excluding an aluminum foil
positive electrode collector.
[0234] <Preparation of Negative Electrode Sheet>
[0235] After 50 parts by weight of graphite (average particle size:
10 .mu.m) as a negative electrode active material was kneaded with
100 parts by weight of a polymer electrolyte solution (4) to be
made in a paste form, the mixture was applied to one surface of a
copper foil negative electrode collector having a thickness of 18
.mu.m at a thickness of 150 .mu.m. The collector was dried at
150.degree. C. for 2 hours to obtain a negative electrode
sheet.
[0236] The content of propylene carbonate contained in this
negative electrode sheet was 15.4% by weight based on the total
weight of the negative electrode sheet excluding a copper foil
negative electrode collector.
[0237] <Preparation of Electrochemical Device>
[0238] Polymer C was press-molded at 210.degree. C. to prepare a
film having a thickness of 18 .mu.m. This film was immersed in a
solution in which the weight ratio of lithium boron tetrafluoride
(LiBF.sub.4) to propylene carbonate is 40:60. The film was left
standing at room temperature for 24 hours, and thereby swollen and
a polymer electrolyte film increased in weight by 48.3% based on
the original weight was obtained.
[0239] The positive electrode sheet and the negative electrode
sheet were laminated interposing this polymer electrolyte film
therebetween to assemble an electrochemical device shown in FIG.
1.
[0240] <Property Evaluation of Electrochemical Device>
[0241] The evaluation of charge and discharge properties of this
electrochemical device was performed as follows. After charging in
a constant-current/constant-voltage charging mode of a maximum
current of 50 mA and a maximum voltage of 4.2 V for 5 hours, the
electrochemical device was discharged to 3.0 V at a constant
current of 10 mA. The discharge volume was 88.3 mAh. Thereafter,
the electrochemical device was recharged in the same condition, and
the evaluation of discharge volume was performed under a constant
current condition shown in Table 8. The results are shown in Table
8.
Example 24
[0242] The present example shows an example of an electrochemical
device of the present invention using an all solid-type polymer
electrolyte of the present invention. FIG. 1 is a schematic
cross-sectional view of this electrochemical device.
[0243] <Preparation of Positive Electrode Sheet>
[0244] A mixture of a positive electrode active material and
conductive auxiliaries obtained in the same manner as in Example
23, lithium bis(pentafluoroethanesulfonyl)imide
{(CF.sub.3CF.sub.2SO.sub.2).sub.2NLi}, propylene carbonate and
Polymer A were charged at a weight ratio of 100:20:30:50, and the
mixture was heated and kneaded at 150.degree. C.
[0245] This kneaded product was extruded into a sheet form at a
thickness of 200 .mu.m on an aluminum foil positive electrode
collector having a thickness of 15 .mu.m. Thereafter, the collector
was dried at 180.degree. C. for 2 hours to obtain a positive
electrode sheet.
[0246] The content of propylene carbonate contained in this
positive electrode sheet was 1,000 ppm or less based on the total
weight of the positive electrode sheet excluding an aluminum foil
positive electrode collector.
[0247] <Preparation of Negative Electrode Sheet>
[0248] Graphite (average particle size: 10 .mu.m) as a negative
electrode active material, lithium
bis(pentafluoroethanesulfonyl)imide
{(CF.sub.3CF.sub.2SO.sub.2).sub.2NLi}, propylene carbonate and
Polymer A were charged at a weight ratio of 50:20:30:50, and the
mixture was heated and kneaded at 150.degree. C.
[0249] This kneaded product was extruded into a sheet form at a
thickness of 150 .mu.m on a copper foil negative electrode
collector having a thickness of 18 .mu.m. Thereafter, the collector
was dried at 180.degree. C. for 2 hours to obtain a negative
electrode sheet.
[0250] The content of propylene carbonate contained in this
negative electrode sheet was 1,000 ppm or less based on the total
weight of the negative electrode sheet excluding a copper foil
negative electrode collector.
[0251] <Preparation of Electrochemical Device>
[0252] Lithium bis(pentafluoroethanesulfonyl)imide
{(CF.sub.3CF.sub.2SO.sub.2).sub.2NLi}, propylene carbonate and
Polymer A were charged at a weight ratio of 20:30:50, and the
mixture was heated and kneaded at 150.degree. C.
[0253] This kneaded product was extruded into a sheet form at a
thickness of 20 .mu.m on the surface of the above-prepared positive
electrode sheet, and then the above-prepared negative electrode
sheet was laminated thereon. After this electrode group was dried
at 180.degree. C. for 2 hours, an electrochemical device shown in
FIG. 1 was assembled.
[0254] <Property Evaluation of Electrochemical Device>
[0255] The evaluation of charge and discharge properties of this
electrochemical device was performed in the same manner as in
Example 23. The results are shown in Table 8.
Comparative Example 13
[0256] The present example shows a comparative example of an
electrochemical device using a polyether-based all solid-type
polymer electrolyte. FIG. 1 is a schematic cross-sectional view of
this electrochemical device.
[0257] <Preparation of Polymer Electrolyte Solution (5)>
[0258] Lithium bis(pentafluoroethanesulfonyl)imide
{(CF.sub.3CF.sub.2SO.sub.2).sub.2NLi} as a electrolyte,
acetonitrile as a solvent and Polymer D were charged at a weight
ratio of 10:100:40, and then mixed and stirred to obtain a
solution.
[0259] <Preparation of Positive Electrode Sheet>
[0260] A positive electrode sheet was obtained in the same manner
as in Example 23 except that the polymer electrolyte solution (5)
was used and the drying temperature was changed to 80.degree.
C.
[0261] The content of acetonitrile contained in this positive
electrode sheet was 1,000 ppm or less based on the total weight of
the positive electrode sheet excluding an aluminum foil positive
electrode collector.
[0262] <Preparation of Negative Electrode Sheet>
[0263] A negative electrode sheet was obtained in the same manner
as in Example 23 except that the polymer electrolyte solution (5)
was used and the drying temperature was changed to 80.degree.
C.
[0264] The content of acetonitrile contained in this negative
electrode sheet was 1,000 ppm or less based on the total weight of
the negative electrode sheet excluding a copper foil negative
electrode collector.
[0265] <Preparation of Electrochemical Device>
[0266] The polymer electrolyte solution (5) was applied onto the
surface of the above-prepared positive electrode sheet, and then
dried to form a coating layer having a thickness of 20 .mu.m.
[0267] The positive electrode sheet having this coating layer and
the above-prepared negative electrode sheet were laminated to
assemble an electrochemical device shown in FIG. 1.
[0268] <Property Evaluation of Electrochemical Device>
[0269] The evaluation of charge and discharge properties of this
electrochemical device was performed in the same manner as in
Example 23. The results are shown in Table 8.
[0270] [Table 8]
TABLE-US-00008 TABLE 8 Discharge condition (mA) and discharge
volume (mAh) 10 mA 50 mA 100 mA Example 23 83.3 mAh 80.9 mAh 77.4
mAh Example 24 81.3 mAh 76.5 mAh 70.9 mAh Comparative 11.4 mAh 5.3
mAh Non- Example 13 dischargeable
Reference Example 4
Production of Polymer F
[0271] 1.0 .mu.mol of palladium acetate, 1.2 .mu.mol of
1,3-bis{di(2-methoxyphenyl)phosphino}propane and 50 .mu.mol of
sulfuric acid were dissolved in 100 ml of a mixed solvent of
methanol and water containing 18% water, and this solution was
charged into a 200 ml-volume stainless steel autoclave purged with
nitrogen. Next, 1 mg of 1,4-benzoquinon was added and the autoclave
was hermetically closed, and then the content was heated while
stirring, and at the time point when the inner temperature reached
90.degree. C., ethylene was added until the inner pressure of the
reactor becomes 5.0 MPa. Subsequently, carbon monoxide was added
until the inner pressure of the reactor becomes 8.0 MPa. Stirring
was continued for 4 hours while maintaining the inner temperature
and the inner pressure in this condition. After cooling, the
content was removed therefrom.
[0272] The reaction solution was washed with methanol, and then
dried under reduced pressure to obtain 21.3 g of a polymer. It was
confirmed from .sup.13C-NMR and an infrared absorption spectrum
that this polymer was substantially an alternative copolymer in
which ethylene and carbon monoxide were alternatively polymerized
(hereinafter, referred to as "Polymer F"). This Polymer F had a
weight average molecular weight of 75,000.
Reference Example 5
Production of Polymer G
[0273] Completely the same operation as in Reference Example 4 was
performed except that propylene was used in place of ethylene in
Reference Example 4.
[0274] The reaction solution was washed with methanol, and then
dried under reduced pressure to obtain 18.7 g of a polymer. It was
confirmed from .sup.13C-NMR and an infrared absorption spectrum
that this polymer was substantially an alternative copolymer in
which propylene and carbon monoxide were alternatively polymerized
(hereinafter, referred to as "Polymer G"). This Polymer G had a
weight average molecular weight of 47,000.
Example 25
[0275] 60 parts by weight of lithium
bis(trifluoromethanesulfonyl)imide {(CF.sub.3SO.sub.2).sub.2NLi} as
an electrolyte salt was mixed with and dissolved in 40 parts by
weight of water to make a solution having a concentration of 60% by
weight (hereinafter, referred to as "Solution B"). 100 parts by
weight of this solution and 55 parts by weight of Polymer F were
charged into an autoclave and the mixture was heated and stirred at
120.degree. C. to obtain a transparent viscous solution.
[0276] After 0.1 parts by weight of hexamethylenediamine as a
crosslinking agent was added to 100 parts by weight of this viscous
solution, the mixture was cast to a thickness of 500 .mu.m on a
glass plate. Thereafter, the cast mixture was dried under
atmospheric pressure at 80.degree. C. for 1 hour to thereby obtain
a slightly sticky gel-type polymer electrolyte in a film form.
[0277] The weight ratio of water to the total of Polymer F and
water determined by .sup.1HNMR measurement at this time point was
25.3% by weight. Here, the NMR measurement was performed using
JNM-LA400 manufactured by JEOL Ltd. The ionic conductivity of this
gel-type polymer electrolyte was measured at 30.degree. C. and
0.degree. C. in an alternating current of 1 KHz. The results are
shown in Table 9.
Example 26
[0278] The same operation as in Example 25 was performed except
that the drying hour at 80.degree. C. was changed to 3 hours in
Example 25. As a result, a substantially non-sticky gel-type
polymer electrolyte in a film form was obtained.
[0279] The weight ratio of water to the total of Polymer F and
water was 18.6% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 9.
Example 27
[0280] The same operation as in Example 25 was performed except
that the drying hour at 80.degree. C. was changed to 6 hours in
Example 25. As a result, an absolutely non-sticky gel-type polymer
electrolyte in a film form was obtained.
[0281] The weight ratio of water to the total of Polymer F and
water was 9.2% by weight at this time point. The ionic conductivity
of this gel-type polymer electrolyte was measured at 30.degree. C.
and 0.degree. C. in an alternating current of 1 KHz. The results
are shown in Table 9.
Example 28
[0282] After a viscous solution obtained in the same manner as in
Example 25 was cast to a thickness of 500 .mu.m on a glass plate,
the cast solution was dried under atmospheric pressure at
120.degree. C. for 3 hours. Thereafter, the glass plate was placed
in a vacuum dryer set at 150.degree. C. and further dried for 10
hours. As a result, an all solid-type polymer electrolyte in a film
form having a water content of 1,000 ppm or less determined by
.sup.1HNMR measurement was obtained.
[0283] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table 9.
Comparative Example 14
[0284] The ionic conductivity of Solution B used in Example 25 was
measured at 30.degree. C. and 0.degree. C. in an alternating
current of 1 KHz. The results are shown in Table 9.
[0285] [Table 9]
TABLE-US-00009 TABLE 9 (Weight of solvent)/ Ionic (Weight of
conductivity solvent and (mScm.sup.-1) Properties of high polymer)
Upper row: 30.degree. C. polymer (% by weight) Lower row: 0.degree.
C. electrolyte Example 25 25.3 11.4 Self-supporting 7.9 film having
slight stickiness but causing no exudation of liquid Example 26
18.6 9.5 Self-supporting 5.9 film causing no exudation of liquid
Example 27 9.2 7.8 Self-supporting 4.3 film causing no exudation of
liquid Example 28 0 5.5 Self-supporting 1.5 film causing no
exudation of liquid Comparative 100 52.4 Liquid Example 14 31.3
Example 29
[0286] 40 parts by weight of lithium boron tetrafluoride
(LiBF.sub.4) as an electrolyte salt was mixed with and dissolved in
60 parts by weight of .gamma.-butyrolactone to make a solution
having a concentration of 40% by weight (hereinafter, referred to
as "Solution C"). 100 parts by weight of this solution and 60 parts
by weight of Polymer G were charged and the mixture was heated and
stirred at 120.degree. C. to obtain a transparent viscous
solution.
[0287] After this viscous solution was cast to a thickness of 500
.mu.m on a glass plate, the cast solution was dried under
atmospheric pressure at 120.degree. C. for 2 hours. As a result, a
gel-type polymer electrolyte in a film form having slight
stickiness was obtained.
[0288] The weight ratio of .gamma.-butyrolactone to the total of
Polymer G and .gamma.-butyrolactone determined by .sup.13CNMR
measurement was 28.8% by weight at this time point. The ionic
conductivity of this gel-type polymer electrolyte was measured at
30.degree. C. and 0.degree. C. in an alternating current of 1 KHz.
The results are shown in Table 10.
Example 30
[0289] The same operation as in Example 29 was performed except
that the drying condition was changed to drying at 120.degree. C.
for 3 hours in Example 29. As a result, a substantially non-sticky
gel-type polymer electrolyte in a film form was obtained.
[0290] The weight ratio of .gamma.-butyrolactone to the total of
Polymer G and .gamma.-butyrolactone was 18.5% by weight at this
time point. The ionic conductivity of this gel-type polymer
electrolyte was measured at 30.degree. C. and 0.degree. C. in an
alternating current of 1 KHz. The results are shown in Table
10.
Example 31
[0291] The same operation as in Example 29 was performed except
that the drying condition was changed to drying at 120.degree. C.
for 6 hours in Example 29. As a result, an absolutely non-sticky
gel-type polymer electrolyte in a film form was obtained.
[0292] The weight ratio of .gamma.-butyrolactone to the total of
Polymer G and .gamma.-butyrolactone was 8.4% by weight at this time
point. The ionic conductivity of this gel-type polymer electrolyte
was measured at 30.degree. C. and 0.degree. C. in an alternating
current of 1 KHz. The results are shown in Table 10.
Example 32
[0293] 100 parts by weight of Solution C obtained in the same
manner as in Example 29 and 80 parts by weight of Polymer G were
charged into an autoclave, and the mixture was heated and stirred
at 120.degree. C. to obtain a transparent viscous solution.
[0294] After this viscous solution was cast to a thickness of 500
.mu.m on a glass plate, the cast solution was dried under
atmospheric pressure at 120.degree. C. for 1 hour. Thereafter, the
glass plate was placed in a vacuum dryer set at 150.degree. C. and
further dried for 10 hours. As a result, an all solid-type polymer
electrolyte in a film form having a .gamma.-butyrolactone content
of 1,000 ppm or less determined by .sup.13CNMR measurement was
obtained.
[0295] The ionic conductivity of this all solid-type polymer
electrolyte was measured at 30.degree. C. in an alternating current
of 1 KHz. The result is shown in Table 10.
Comparative Example 15
[0296] The ionic conductivity of Solution C used in Example 29 was
measured at 30.degree. C. and 0.degree. C. in an alternating
current of 1 KHz. The results are shown in Table 10.
[0297] [Table 10]
TABLE-US-00010 TABLE 10 (Weight of solvent)/ Ionic (Weight of
conductivity solvent and (mScm.sup.-1) Properties of high polymer)
Upper row: 30.degree. C. polymer (% by weight) Lower row: 0.degree.
C. electrolyte Example 29 28.8 3.1 Self-supporting 2.3 film having
slight stickiness but causing no exudation of liquid Example 30
18.5 2.8 Self-supporting 2.1 film causing no exudation of liquid
Example 31 8.4 2.1 Self-supporting 1.7 film causing no exudation of
liquid Example 32 0 1.9 Self-supporting 0.9 film causing no
exudation of liquid Comparative 100 3.4 Liquid Example 15 2.2
Example 33
[0298] The present example shows an example of an electrochemical
device of the present invention using a gel-type polymer
electrolyte of the present invention. FIG. 1 is a schematic
cross-sectional view of this electrochemical device.
[0299] <Preparation of Polymer Electrolyte Solution (6)>
[0300] Lithium boron tetrafluoride (LiBF.sub.4), propylene
carbonate and Polymer F were charged at a weight ratio of 40:60:60,
and the mixture was heated and stirred at 120.degree. C. to obtain
a viscous solution.
[0301] <Preparation of Positive Electrode Sheet>
[0302] LiCoO.sub.2 (average particle size: 5 .mu.m) as a positive
electrode active material, and graphite and acetylene black as
conductive auxiliaries were dry-mixed at a weight ratio of
100:5:2.5.
[0303] After 100 parts by weight of a polymer electrolyte solution
(6) and 100 parts by weight of the mixture of a positive electrode
active material and conductive auxiliaries were kneaded to be made
in a paste form, the mixture was applied to one surface of an
aluminum foil positive electrode collector having a thickness of 15
.mu.m at a thickness of 200 .mu.m. The collector was dried at
150.degree. C. for 2 hours to obtain a positive electrode
sheet.
[0304] The content of propylene carbonate contained in this
positive electrode sheet was 11.2% by weight based on the total
weight of the positive electrode sheet excluding an aluminum foil
positive electrode collector.
[0305] <Preparation of Negative Electrode Sheet>
[0306] After 50 parts by weight of graphite (average particle size:
10 .mu.m) as a negative electrode active material was kneaded with
100 parts by weight of a polymer electrolyte solution (6) to be
made in a paste form, the mixture was applied to one surface of a
copper foil negative electrode collector having a thickness of 18
.mu.m at a thickness of 150 .mu.m. The collector was dried at
150.degree. C. for 2 hours to obtain a negative electrode
sheet.
[0307] The content of propylene carbonate contained in this
negative electrode sheet was 16.5% by weight based on the total
weight of the negative electrode sheet excluding a copper foil
negative electrode collector.
[0308] <Preparation of Electrochemical Device>
[0309] The polymer electrolyte solution (6) was applied onto the
surface of the above-prepared positive electrode sheet, and then
dried at 100.degree. C. for 1 hour to form a coating layer composed
of polymer electrolyte having a thickness of 20 .mu.m.
[0310] The positive electrode sheet having this coating layer and
the above-prepared negative electrode sheet were laminated, and
then each of lead terminals was mounted on a positive electrode and
a negative electrode. The resulting laminate was placed in a
battery container to assemble an electrochemical device shown in
FIG. 1.
[0311] <Property Evaluation of Electrochemical Device>
[0312] The evaluation of charge and discharge properties of this
electrochemical device was performed as follows. After charging in
a constant-current/constant-voltage charging mode of a maximum
current of 50 mA and a maximum voltage of 4.2 V for 5 hours, the
electrochemical device was discharged to 3.0 V at a constant
current of 10 mA. The discharge volume was 95.3 mAh. Thereafter,
the electrochemical device was recharged in the same condition, and
the evaluation of discharge volume was performed under a constant
current condition shown in Table 12. The results are shown in Table
11.
Example 34
[0313] The present example shows an example of an electrochemical
device of the present invention using an all solid-type polymer
electrolyte of the present invention. FIG. 1 is a schematic
cross-sectional view of this electrochemical device.
[0314] <Preparation of Positive Electrode Sheet>
[0315] A mixture of a positive electrode active material and
conductive auxiliaries obtained in the same manner as in Example
33, lithium bis(pentafluoroethanesulfonyl)imide
{(CF.sub.3CF.sub.2SO.sub.2).sub.2NLi}, propylene carbonate and
Polymer F were charged at a weight ratio of 100:20:30:50, and the
mixture was heated and kneaded at 150.degree. C.
[0316] This kneaded product was extruded into a sheet form at a
thickness of 200 .mu.m on an aluminum foil positive electrode
collector having a thickness of 15 .mu.m. Thereafter, the collector
was dried at 180.degree. C. for 2 hours to obtain a positive
electrode sheet.
[0317] The content of propylene carbonate contained in this
positive electrode sheet was 1,000 ppm or less based on the total
weight of the positive electrode sheet excluding an aluminum foil
positive electrode collector.
[0318] <Preparation of Negative Electrode Sheet>
[0319] Graphite (average particle size: 10 .mu.m) as a negative
electrode active material, lithium
bis(pentafluoroethanesulfonyl)imide
{(CF.sub.3CF.sub.2SO.sub.2).sub.2NLi}, propylene carbonate and
Polymer F were charged at a weight ratio of 50:20:30:50, and the
mixture was heated and kneaded at 150.degree. C.
[0320] This kneaded product was extruded into a sheet form at a
thickness of 150 .mu.m on a copper foil negative electrode
collector having a thickness of 18 .mu.m. Thereafter, the collector
was dried at 180.degree. C. for 2 hours to obtain a negative
electrode sheet.
[0321] The content of propylene carbonate contained in this
negative electrode sheet was 1,000 ppm or less based on the total
weight of the negative electrode sheet excluding a copper foil
negative electrode collector.
[0322] <Preparation of Electrochemical Device>
[0323] Lithium bis(pentafluoroethanesulfonyl)imide
{(CF.sub.3CF.sub.2SO.sub.2).sub.2NLi}, propylene carbonate and
Polymer F were charged at a weight ratio of 20:30:50, and the
mixture was heated and kneaded at 150.degree. C.
[0324] This kneaded product was extruded into a sheet form at a
thickness of 20 .mu.m on the surface of the above-prepared positive
electrode sheet, and then the above-prepared negative electrode
sheet was laminated thereon. After this electrode group was dried
at 180.degree. C. for 2 hours, an electrochemical device shown in
FIG. 1 was assembled.
[0325] <Property Evaluation of Electrochemical Device>
[0326] The evaluation of charge and discharge properties of this
electrochemical device was performed in the same manner as in
Example 33. The results are shown in Table 11.
[0327] [Table 11]
TABLE-US-00011 TABLE 11 Discharge condition (mA) and discharge
volume (mAh) 10 mA 50 mA 100 mA Example 33 95.3 mAh 92.7 mAh 88.3
mAh Example 34 89.3 mAh 86.1 mAh 83.2 mAh Comparative 11.4 mAh 5.3
mAh Non- Example 13 dischargeable
INDUSTRIAL APPLICABILITY
[0328] The polymer electrolyte of the present invention can be used
for non-aqueous primary batteries such as a metal lithium battery,
aqueous secondary batteries such as an aqueous ion battery,
non-aqueous secondary batteries such as a lithium ion secondary
battery, non-aqueous electric double layer capacitors, hybrid
capacitors and other electrochemical devices.
BRIEF DESCRIPTION OF THE DRAWING
[0329] FIG. 1 is a plan view and a longitudinal sectional view
showing an example of an electrochemical device of the present
invention.
DESCRIPTION OF REFERENCE NUMERALS
[0330] 1 Positive electrode [0331] 2 Negative electrode [0332] 3
Positive electrode lead terminal [0333] 4 Negative electrode lead
terminal [0334] 5 Polymer electrolyte [0335] 6 Battery
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